The proposed research involves the development of new methods for the synthesis of complex organic molecules and the application of these methods to the total synthesis of biologically important natural products and hormones. The first section deals with the synthesis of taxusin, a member of the taxane family of natural products. Representatives of this family, i.e., taxol, exhibit anti-leukemic and antimitotic properties. The second section describes an efficient enantiospecific synthesis of the steroid nucleus, in particular the adrenocortical steroids. The synthesis utilizes two new classes of organinc molecules, bridgehead enol lactones and bridgehead enol ethers. The third section is an exploratory program in synthetic organic chemistry aimed at the construction of nitrogen containing heterocycles.